Added tentative functionality to xsh_kill, needs testing, COMPILES
Added jobkill to the shell files and makefile so that it is compiled and recognized as a command in commandline.
Delete .xsh_jobskill.c.swo
Delete .jobsgroup.c.swo
Delete xsh_jobskill.c

Changed to jobkill
Made things compile
Merge
Merge branch 'jobs_kill' of https://github.com/cmh6807/xinu-arm-job-control-shell into jobs_kill
Fix merge
Merge branch 'job_control_shell' of https://github.com/cmh6807/xinu-arm-job-control-shell into jobs_kill
Delete .jobsgroup.h.swo
Merge branch 'jobs_kill' of https://github.com/cmh6807/xinu-arm-job-control-shell into jobs_kill
Switched to jobs->ID